反应详情

3-Methyl-4-nitroaniline was treated with iodine and silver sulfate to give 2-iodo-5-methyl-4-nitroaniline. Treatment of the nitroaniline with 2-(trimethylsilyl)acetylene under the typical Sonogashira conditions gave 5-methyl-4-nitro-2-[(trimethylsilyl)ethynyl]aniline, which was treated with a base in an aqueous methanolic solution to give 2-ethynyl-5-methyl-4-nitroaniline. A subsequent base-induced cyclization at an elevated temperature gave 5-nitro-6-methylindole, which was treated under a high pressure hydrogenation condition to provide 5-amino-6-methylindole.